In the current application of Ti: sapphire (Ti: Al2O3) available on the market, a bulk crystal is mainly used as gain medium for a Ti: sapphire laser. There is a significant limit on practical application due to a bulky laser device, resulted from a need for a high wattage pumping source.
Some academic groups have invested the research and development of the structure of Ti: sapphire integrated optical waveguide, which is fabricated mainly by growing a Ti: sapphire crystal layer on a substrate, and then etching the grown Ti: sapphire crystal. The manufacturing process is difficult and complicated, as well as the finished waveguide still far from commercialization due to its considerably high transmission loss.